The present invention relates to a rotary connector for achieving electrical signal transfer between electric apparatuses/parts respectively provided at a stationary member and a rotary member, and more particularly, to an electric connecting apparatus capable of easily and reliably establishing electrical connection between a rotary connector and a wiring harness which is in turn used for establishing electrical connection between the rotary connector and an electric apparatus/part.
A typical rotary connector is equipped with a stationary casing provided on the side of a stationary member, a rotary casing provided on the side of a rotary member and rotatably fitted to the stationary casing, and a flexible flat cable housed between these casings in a spiral form. The flat cable is electrically connected to an electric apparatus/part (an electrical machinery and apparatus or a part of the same) through, e.g., a wiring harness. This type of rotary connector is mounted on an automotive steering device, for instance. In this case, the stationary casing of the rotary connector is fixed on a steering column, while the rotary casing is fitted to a steering shaft. The flat cable is further connected, via wiring harnesses, to various switches, an air bag inflator, etc. each provided on a steering wheel, and to a controller, a shock detecting sensor, a diagnosis unit, etc. respectively provided on a car body. When a driver operates the steering wheel to cause the rotary casing to rotate in unison with the steering shaft, the flat cable is caused to be wound or unwound. According to the aforementioned arrangement, the electrical signal transfer between the electric apparatus/part on the steering wheel side and the corresponding electric apparatus/part on the car body side can be achieved through the rotary connector, regardless of the rotary position of the steering wheel.
Conventionally, in the case of using wiring harnesses for electrical connection between a flat cable and electric apparatuses/parts, the flat cable and the wiring harnesses were connected by welding or the like before or after assembling a rotary connector. When welding the flat cable and the wiring harnesses before assembling the rotary connector, the rotary connector is assembled in such a manner that the flat cable is housed in between a stationary casing and a rotary casing and the wiring harnesses are disposed outside the two casings. Also, when welding the flat cable and the wiring harnesses after assembling the connector, the connector is assembled such that both ends of the flat cable are exposed outside the connector. Thus, an irksome or complicated welding process and irksome connector assembly are required for the electrical connection between the flat cable and the wiring harnesses.